Intercommunicating telephone system



Parme-e July 27, 1926.

UNl'rEo STA' Es Pain:Nrl OFFICE.

EGBEM' A. REYNOLDS, oE WEEHAWKEN, NEW JERSEY, AssIGNoE, EYMEsNE As-SIGNIENTS, TOLUDIIHONE COMPANY OF AMERICA, OF NEW YORK,

rou'rIoN'oE DELAWARE,

nrrEaoommUNicArnve TEEEPHQNE 'sYs'rEm- Lppneauon inea' July 1c,

` V station. A further object of the :invention is to provideindependence o fcircuit connec tionbetween the master'station and therespective local stations and for connection of the master station withthe desired local station while excluding the 'remaining local stations.A further object is to. provide a circuit arrangement comprising twoinduction coils, connected vin separately in. the respective .in-comingand out-going commutallic lines.

further object of the invention is to provide means operable from anylocal station for setting an indicator'orthe like at the masten stationto indicate the local sta- 'tion calling, also toi provide means formaintaining such indication during the communication and .toautomatically release'such-indication upon termination of communicationwith vsuch local station, preferablyunder control of the-masteroperator.

In accordance with the invention, inthe preferred-forms thereof, themaster station is provided with -la suitable indicator. means providedat the respective local station for setting the indication correspondingto such local station, keyesetting means provided at the master stationfor closing thel circuit be-` tweenthe masterd stations and the localstation andexcludingthe circuits of the other stations I'and meansprovided for releasing such indication upon hanging up the receiver atthe master-station.

vIn such preferred forms of thel invention,

in the event of two ormore local stations.

sending in their respectivev indications, the

'- indications o. all -su'ch stations are reta-ined in lvisible positionduring the successive periods of c0mmunication-with the severallocal-stations. until the master receiverat the master station is.placed on its hook.

Further features and objects of the inven- 1920. semi 1m .scaricaY tionwillbe more fully understood from the drawings, in which- Fig. 1 is a`diagramof a simple form of `system comprising the xmaster station and'a single local station and embodying myff invencion;7

Fig. 2 is amore elaborate form of system embodying my` inventionandcomprising the master station and four local stations;

station and three local stations, embodying 'my invention; V

Y., a con.- i

Fig. Sis a diagrammatic view of a master Fig.,4 is a detail sideelevation of a switch i and control mechanism forming part of the'arrangement shown in theaforesaid figures;

and v Fig. 5 is a detail view corresponding' to Fig.`4 showing theoperated parts'of the same in circuit closing position.

Referring to the form of the system shown in Fig. '1, theA masterstation is indicated at' 1 and comprises the master transmitter; 2 andthe masterreceiver 3. The single station is indicated at 4 and comprisesthe local transmitter 5 and the local receiver 6 'In the formof theinvention as show n, the. cir- .a

cuit is-fullv' metallic, that is 'to say, the con` duction of the voicecurrents transmitted Ato 6and from the respective stations aretransmitted over solely metallic conductors, and amplified by inductioncoils. The leads 7, 8 of the master transmitter 2 are connected at theplug-in ,points`9,l 10, to the' line conductor 11 andthe lead 12. lTheconductor 11 is connected at -13 to one terminal ofthe f primary coil 14of the -induction coil 1 5, the

'other terminal 16 being connected by` the.

'conductor 17 to the line conductor 18 connecting at 19 to the lead 19with the plugin point 20 with the lead 21 connected to one' terminal ofthe local transmitter 5. 4The other lterminalpf the local transmitter` 5is are connected at the respective plug-in points 33, 34 to the leads35, 36connected lextending tc the plug-in point 4 20. The4 positiveterminal 50 of the battery 45 is connected bythe lead 51 to the plug-inpoint 52, at the master station, to the lead 53 connectingr with thecontact 54, associated with `the contact 55, for purposesmorefullydescribed hereinafter. The contact 55 is connected bythe leadj 56 at theplug-in point y 57 to the lead 58 connected at 30 to the lead Aaus 12,whereby upon removal by the master operator of the mster receiver 3fromits hook, the contacts 54, 55, are brought into closed engagementand the circuit of the master transmitter 2 is connected through thebattery with the'local receiver 6 through the energization of theprimary coil 14 inducing amplified energization of its secondary coil44, as set forth hereinabove. Similarly, the closure of thecontacts 54,55,

effect-s the closing ofthe metallic circuit between the master receiver3 and the local transmitter 5 through the primary coil 26, thenceinductively under anipliiication through the secondary coil 37 of theinduction coil 27.

It will thus be seen that the master transmitter when. in operativeposition, is in metallic connection ewith its primary coil of oneinduction coil, whose secondary is in metallic connect-ion with thereceiver of the local station; also, that the local transmitter is inmetallic connection with the primary coil of a second and independentinduction coil andfthat the master receiver is in metallicconnection.with the secondary of such secondlinduction coil.

For the purpose of effecting signaling by the `local operator to themaster station, I

have rovided thel buzzer 60 connected on one side by the lead 61 to thepositive ter-v minal of the battery'45, and connected on. the othersideto the line conductor 62, con-` nected at 63 to the line conductor43, thence connected at 64 to the lead 65', running to the contact 66 ofthe push button 67, lthe other contact 68 of the push button 67 beingconnected by the lead 69-at 70 to the.

lead-21, connected through the lead 19 to `the 7line conductor' 47connected to the negative terminal 46.4 Such circuit relation (affordsdirect closure 'of the signalling system rthrough the battery.

local station form of `my invention, upon the local operator closing thepush button 67 to audibly indicate through the buzzer that communicationis desired, with the master operator, the master operator upon removinghis receiver 3 from its hook, closes the contacts 54, 55, and thusconnecting the metallic line circuits betweenv the master transmitter 2and the local receiver 6, and the metallic line'circuits between thelocal transmitter 5 and the master receiver 3, through the battery 45,each metallic circuit being independent of the other.

In Fig. 2, I have represented the type of my invention embodying themaster station 8O comprising the master transmitter 81 and a masterreceiver 82, and four local stations indicated respectively by thebrackets 83, 84, 85 86. The plug-in points 87, 88 and 89, 9() of themaster station correspond to' the plug-in point of the master stationshown in Fig. 1. The lead 91 from the plug-in point 88 connects with thelead 92 connecting with the plug-in point- 93, at the master station,and thence with the lead 94 and contact 95.

The Contact 96 coacting with the contact 95 is connected by the lead97through the plugin points 98 to the conductor 99 leading to the positiveterminal 100 of the battery 101.

The set of contacts 95, 96 correspond to the set of contacts 54, 55,aforesaid, and are arranged to be in open position: when the masterreceiver 82 is out of use, i. e., suspended on its usual hook, Aand tobe 'placed in closed position when the master receiver 82 is removedfrom its hook.

The several local stations are each pro vided with a similar set ofplug-in points, eachset comprising four in number. These plug-in pointsare designated by like reference numbers, to wit, 102, 103, 104, 105,corresponding to the aforesaid plug-in points 40, 41, 23 and 20 forconnection with the respective leads 38, 39, of each local receiver 6,and the leads 21, 22, of each local transmitter 5. Each local station issimilarly provided with the4 push button 67 compris- 1 ing the contacts66, 68, as aforesaid, and connected by the leads 65, 69 to therespective local leads 39 and 21, respectively. In ,view of the localtelephone set at, the other local stations 84, 85, 86 being similar tothat shown at local station 83', the parts thereof have been omitted andare deemed not to require specific'description.

The induction coils 110 and 111 are located at the master station, theterminals of the primary coil 112 ofthe induction coilf110 beingrespectively connected bythe lead 113 to the plug-inpoint 87 and by thelead 114 to the negativer terminal `115 of the battery V101. Oneterminal' ofthe secondary coil 116 ofthe induction coil 110 is connectedto the common line.119,y connecting togetherthe respective local plug-inpoints 103 of the severallocal stations.

The other'terminal of thesecondary coilv 116 of induction coil 110 isconnected by the lead 120 to the common conductor 121l indicated as astrap interconnectingl the contacts 122, each of. the sets of contacts 123 corresponding in number to the number .1

of local stations. The other contact .124 'of each set of contacts 123is arranged to4 be .closed by'its key 125. Each key 125 is positione'dpreferably at the master station;

'upon operation of the buzzer or the. like by. any local operator, themaster operator def resses the key 125 corresponding to vsuch ocalstation, fand thereby'connects such local statlon with the masterstation,A and eX- cluding all other local-stations.

Each contact 124 of such set 123 of contacts is connected to the lineconductor 126- tothe lug-in point1102 atits local station.

The E tion, is connected on one side through the line cond'uctor106 toeach plug-'in point 103 of the respective' local stations and thus toeach lead 39 and contact 66 of each local push-button 67 and isconnected on the other side through the lead 107 to the positiveterminal 100 of the battery 101; The remainder'of the circuit of thebuzzer is completed through the negativeterminal 115 of the'battery 101,through the conductor `114, thence through the common connector or strap130 ofthe enunciator 131 thence through the lead 1 32 of one terminal ofthe enunclator-magnet 133, the-nce throughits other terminal through theline conductor 134 to the plug-in terminal 105 and thence to theremaining contact 68 of its push-button 67. Upon energization ofthemagnet 133 of the cnunciator 131 corresponding to the localV station,its indicator or drop 135 is placedin visible position asin the usual.vlsual'enunclaton and retained by its mag- Hnet 1n such vlsibleposition after release of pressure at the push-button 67 by the localoperator. Arrange-d correspondingly with set 136 being connected'throughthe common 'lead 140l or conducting strap, through the transmitter 81,thence through the plug-in lead 141, the one terminalo'the coil 142ofthe inductioncoil 111, thence through the lead 143 and lead 91 to theplug-inv point 88 of the master'station and thus to the master point 87thence through the primary 11.2

4of the induction' coil 110, thence through the uzzer 140, located atthe master staconductor 114 leading to the negative/ ter' minal 115 ofthe battery 101, thence through the positive terminal 100 of battery101, lead 99, contacts 96, 95, and thence through the lead 91completing. the circuit of the master transmitter 81.

In such arrangement, two induction *coils 'are employed, irrespective ofthe number of local stations, each local station when connected 1nhaving its local receiver in metallic circuit with the mastertransmitter through one induction coil and its local transmitter linmetallic circuit with the master receiver through the other induction.coil, 'whileall of the-other local circuits, remain out of circuit.

In Fig. 3, I have-indicated schematically I such system, the mastertransmitter being shown at 81 and the master vreceiver at 82, the:contacts 95, 96 being operated in the usual-manner by the. stem 145.rIfhe ltWoinduction coils 110 and 111 are shown positioned Within thecasing '146 of the combined enunciator 147.

To the stem 145 is also 'attached the' arm 15,0 to' which is secured the`downwardly extending toe 151, see Figs; 3, 4 and 5, cooperating withthe intermittent contact maker 152, shown in the. form of a toothedcircular member and coacting with the spring toe'151 is related to thecontact 148 so that as any tooth 153-depresses the spring 154 of thecontact 148 toits maximum extent," the contact button 155 of the contact148-is in engagement with the contactbutton-156 of the' contact 149.

The several local .stations designated 83, 84,85, etc. correspond to thesimilarly designated local stations indicated in Fig. 2, and each localstation isl equipped with its sensitive transmitter 5 and amplifyingreceiver 6, located Within a common housing 160,

provided. at its front with ,the spaced, inllo clined stripsv161enabling the sound waves vto -pass therethrough and concealing thetransmitter 5 and receiver 6. The push but- 4in the nature of aratchet.` 'Each -tooth 15 3 ton 67 is conveniently positioned in thetopp of .each housing 160, as indicated. 'The re-v spective cables -162include the line conductors of the communication and signallingsystemsreferred to specifically hereinabove.

Assuming the master operator desires .to-

call any station, say No. 1, to wit, the station indicated in Fig; 2 byreference No.

"83, the -key 125, sce Fig. 3, corresponding to such station, -isdepressed thereby closing switches 123 and 136 respectivelycorresponding to such stationl andthus closinglthe circuit connect-ingthe secondary 116 of the induction coil with the receiver 6 of suchlocal station fand the primary of the induction coil 111 withy the localtransmitter of such station. Upon the master operator "removing hismasterreceiver 82 from its hook 157,-the hook 157 underaction f ,eratorcalls through his transmitter 2 hello with the name of the partydesired,

or foigany party'in general, and the response at the local station iseffected by suchper l son answerlngjat a distance from the localtransmitter housed in -its'casing 160. U on completion of thecommunication desired L by the master operator with the local party,

`the master operator hangs his receiver 82 on its hook 157, causing thestem 145 to be depressed, whereby the spring arm 151 engages a tooth 153causing an advanced tooth 153 in its rotation to engage the toe 154 ofthe contact 148 and thus closing the circuit between the contacts 148,149, through the line 157 see Fig. 2 connecting at 157,L .with the line158 leading to one'side of the reset. or restoring magnet 159 andconnected on the other side through the lead 159'L to the lead 1 14connecting with' the negative terminal -115 of the battery 101, thepositive side 100 of the battery 101 being connected theroughl theconductor 99 and lead 97 vwith'tlie contact 149. -The reset magnet.1 159is provided with a suitable armature 160 arranged in -any approvedmanner relative to the keys 125 to reset. the keys 125 to normalposition. Such closure of the contacts 148,` `149 also closes'thecircuit through the battery and the restore magnets 161 of theenunciator to cause the .drop 135 to be returned tov neutral, in whichcircuit connection the contact 148 is connected through the lead 157 atthe point 157*l to the lead 162 to thestrap 163 connected through the`conductor 164 to gne end of the restore magnet 161, the other v end ofthe restore lmagnet 161 being connected through lthe conductor 165 tothe strap 130 connected. through the -lead 114 tothe negative terminal115 of tle battery 101, the positive terminal being vcoxmected to thelead- 99v to the lead 97 connected to the' other contact 149.

Preferably, each local receiver embodies the construction set forth andclaimed in .the application entitled Sound reproducing instrument,Serial No. 183,215, filed July 28, 1917, filed by me jointly WlithlQeElbertA. Reynolds', and each local transmitter preferably is of theconstruction set forth and claimed in the copending application SerialNo. 240,418, entitled Audiphones, filed June 17, 1918, by De Elbert A.Reynolds,

maining local stations are excluded from the ycircuita'lso that thesignalling circuit operating the enunciator at thel master stationembodies a conductor-leading from each push button or equivalent, at thelocal station connected with the secondary circuit of one induction coiland the primary circuit of the other induction coil; alsoi that upon themaster operator placing his reu n d u c celver on 1ts hook, theintermittent current transmitted from the battery -passes through a dualcircuit connecting in parallel the restoring magnet of the enunciatorand the restoring magnet of the keys, such intermittent .energizationbeing preferred for ythe purposefof causing all circuits to be in lopenposition when the master receiver and its hook have attained its finalor fuli nonoperative position. Whereas I have .described my inventio byreference to specific form-s thereof, it will be understood that manychanges and modifications may bey made Without departing from the spiritof the inventiom as delined by the appended claims.

What I do claim and desire to have protected by Letters Patent is 1. Thecombination with a master transmitter and a master receiver, of aplurality of local stations, each local station 'comprising a localtransmitter, a local receiver, 'a circuit foreach local `transmitterfullyjclosed at all times through its localJ transmitter an'd acorrelated circuit for each local receiver fully closed at lall timesthrough its local receiver, an induction Coil connected in common withthe localreceiving circuits, a second induction coil connected in commonwith the local transmitter circuits, and

means for connecting in at-will the set of correlated local circuits ofany desired local station with said master transmitter and saidmasterreceiver while maintaining out of circuit at all times theremaining sets of local circuits.

2. The combination with a master station -through its local receiver, asource of electrical energy, an inductioncoil, leads connecting themasterJ transmitter with the primary of said induction coil, a secondinduction coll, means t,connecting the secondary of sai d secondinduction'coil with said master receiver, means connecting atwill thevlocal circuit through. the desired local receiver 45 the aforesaidcorrelated circuits of any de- J 'sired local station,

cated at the master station, operable means' lated local circuit of the'Y 4said two'connecting mon conductors.

v connecting t tions, each throughits local receiver, .trical energy,

vsignalling said first 'named connecting means and ter receiver,

with the secondary of saidfirst induction coil, means for .connectinat'will the correesiredl local transmitter .with the primary ofsaid-induction coil and manually operated means located.l at

the respective local stations -for signalling the master station, saidsignalling means and tion comprising of said second induction coil with'said'masmeans connecting at will the' local` circuit through the desiredlocal reter receiver,

ceiver' with the secondary of `said iirst induction coil, means local'transmitter lWith the'primary of said induction coil and manuallyoperated means locatedA at the respective local stations for the masterstation, said signaling means including a conductor common-with aconductor common withsaidsecond named connecting means.

'4. The combination with a master station comprising a mastertransmitter and amaster receiver,`of ya plurality of local stationseachlocal stationcomprising a local transmitter and alocal receiver, a localcircuit normally closed through its local transmitter, a correlatedlocal circuit normally closed through its local receiver, a source ofelectrical energy, selector circuit means for con necting the masterstation with the set of announcing means lolocated at the respectivelocal stations for operating said announcing means and means forautomatically restoring said selector cir-f cuit means and saidannouncing neutrali .means to 5. The combination with a master stationcomprising a each local station comprising alocal transmittel.' and alocal receiver, a local circuit normally 4closed through its localtransmitter, a correlated. local circuit normally.

closed through its local receiver, a source of electrical energy,selector ,circuit means for he master station with the set of theaforesaidcorrelated circuits of any desired local station, announcingmeans 1ooperating =means including com- ,means for-connecting at willthe correlated local circuit of the desired master transmitter andamasof a plurality oflocal stations mitter, a hook carried cated at thestation, 4operable means located atthe respective local'stations for,

automatically operated upon electing the master station to non-operativeposition for restoring said selector circuit means and said announcinmeans to neutral.

6. The combination with a master station comprising a master transmitterand a master receiver, of .a plurality of local stations each localstation comprisin a local transmitter an'd av local receiver, a ocalvcirsaid announcing means and means cuit.v normally closed through itslocal trans- 4 mitter, a correlated local circuit normally closedthrough its local-receiver, a source of electrical energy, selectorcircuit means )for connecting the master station with the set of theaforesaid correlated circuits of` any desired local station,;announcingmeans located at the master 'station, operable located 'at therespective local' stations for operating said announcing means and meansautomatically operated upon effecting the master station tonon-operative position for .restoring said selector circuit means andsaid'announcin tral, said automatic restoring means comprising a circuitmeans respectively connectmeans to neu- )ingsaid selector circuitmeansand said annoui'icin'g means inl parallel'v'vith one ,another with' 7.The combination with'ja master station master transmitter anda masterreceiver, of a plurality of local stations each local station comprisinga local trans-l initter and a local receiver, a local circuit normallyclosed-through its localA transmitter, a correlated local circuitnormally closed through its, local receiver, a source ofelectricalenergy,`selector circuit means for connecting themaster-'station with the set of .the aforesaid correlated circuits of'any-delocal station, announcing means lo-" sired cated at the masterstation, operable means located at the respectivelocal stations foroperating said announcing means and means automatically operated uponeili'ecting vthemaster station to `non-operative position for restoringsaid selector .said announcing means to neutral, said automaticrestoring means includinga setl of normally s aced contacts' 'and Ameansfor moving -sai' contacts to closed position ,operable vupon electing.the master receiver to non-operative position.

8. The combination witha' master station comprising a mastertransmitter, a master receiver, a support `for said master transholdingsaid master receiver in its non-operative position,ofaplurality 'oflocal sta- Y tions, a local circuit normally closed throngl its localtransmitter, a correlated local circuit' normally closed through itslocal, ,reciver, a source of electrical energy, an ,enunsaid source, ofelectrical energy.

circuit means and iis by said support for l ciator, restoring means forsaid enunciator, selector circuit means connecting the master stationwith any desired local station, said selector circuit means com rising aplurality 5 of keys corresponding to t e respective local stations,restoring means for said keys, and means operable upon placing saidmaster receiver on said hook for eiiecting intermittent connectlonbetweensaid source and sald v enunciator restoring means an'd saidrestor- 10 ing means for said keys. l

In testimony whereofeI have -signedthis specification this St'h day ofJune; 1920. EGBERT A. REYNOLDS.

